Prepregnancy metformin use tied to lower risk of hyperemesis gravidarum

Metformin treatment prior to conception is associated with a reduced risk for severe nausea and vomiting during pregnancy, according to new research.

The study included 5,414 women who reported their daily medication and substance use in the month before pregnancy and provided data on the level of nausea and vomiting they experienced during pregnancy.

In multivariate logistic regression models, metformin use before the first pregnancy was associated with a 71-percent reduction in the risk of hyperemesis gravidarum (adjusted relative risk [aRR], 0.29, 95 percent confidence interval [CI], 0.12–0.71; p=0.007). Tobacco use was also associated with a risk reduction (aRR, 0.51, 95 percent CI, 0.30–0.86; p=0.011). In contrast, selective serotonin reuptake inhibitor use contributed to a risk increase (aRR, 2.41, 95 percent CI, 1.33–4.38; p=0.004).

Metformin use before the second pregnancy was associated with an 82-percent reduction in the risk for severe nausea and vomiting of pregnancy and hyperemesis gravidarum (adjusted odds ratio [aOR], 0.18, 0.06–0.59; p=0.005). This benefit persisted despite adjustment for the 86 percent reoccurrence risk identified in this study. Conversely, the use of cannabis or selective serotonin reuptake inhibitors before the second pregnancy was each associated with a risk increase (aOR, 3.48, 1.80–6.75; p<0.001 and aOR, 1.84, 95 percent CI, 1.12–3.04; p=0.016, respectively).

Researchers underscored the need to conduct clinical trials to establish the role of prepregnancy metformin use in lowering the risk of hyperemesis gravidarum.